A novel device description is set forth in the instant invention that allows for treatment of fully or partially occluded vessels within the body; usually those vessels being blood vessels. In brief, the instant invention allows multiple therapies to be provided with a single device. One embodiment of the instant invention is to provide a single device/catheter/guide wire that allows for balloon angioplasty of a stenotic lesion in the vasculature and deployment of a device for propping open the vessel with that same device. This is often referred to as an endoprosthesis, but more frequently referred to as a stent or stent-graft. Usually stenosis of a blood vessel is treated by placing a balloon in the narrowed/stenosed area of the vessel and expanding the balloon, which subsequently expands the narrowed vessel, at least temporarily or partly. This balloon expansion is referred to as balloon angioplasty. Unfortunately, too often after balloon angioplasty, the vessel returns to its original xe2x80x98narrowedxe2x80x99 condition. This is referred to as recoil, if it occurs acutely. Subacute or late narrowing may be secondary to restenosis, a complex process described more fully elsewhere in this document. These processes occur in a large percentage of xe2x80x98balloonedxe2x80x99 vessels, sometimes upward of fifty percent. Because of this limited long-term success, balloon angioplasty is frequently used in addition to, or in conjunction with, other therapies such as placement of a stent, stent-graft, or subsequent drug delivery to the area of stenosis or re-stenosis. The additional therapies will hopefully prevent the re-closure of the vessel after balloon angioplasty. These subsequent therapies require the addition of new devices after balloon angioplasty. Hence, it is standard procedure to remove the angioplasty device only to replace it with another device that either delivers the stent or stent-graft, and even another device, which delivers the drug or other therapy. Hence it is the preferred embodiment of the instant invention to provide a device that can expand the vessel via a balloon angioplasty device, but also provide a system that can simultaneously or subsequently deliver a therapy such as a stent or stent- graft or deliver agents/drugs without the removal of the original angioplasty device/catheter.
Conversely, a novel therapeutic device is described in the instant invention that can dilate the narrowed vessel without the use of a balloon and can then deploy a stent or stent-graft with a balloon or with another novel mechanism on the same device.
Further, another preferred embodiment of the instant invention allows for a therapeutic delivery of a drug or other agent to tissue to prevent or treat disease. In particular, during balloon angioplasty, this is accomplished without an additional device being used for this therapy.
The instant invention is primarily, though not exclusively, oriented to the use of technology referred to as tubular braid or braided sleeving. The basic design of tubular braid is well defined later in the patent under a particular xe2x80x98commentsxe2x80x99 section entitled The Tubular Braid or Braided Sleeve Element.
In a first embodiment of the present invention provides an improved device (guide wire or catheter) of the type having an elongate flexible shaft with a proximal end and a distal end. The improvement comprises configuring at least a distal portion of the flexible shaft so that it can assume a shape(s) along its shaft (proximally, mid-section or distally) that will act as a dilator. This guide wire or catheter can be moved along the lumen (artery, vein, intestine, stent, graft, or other hollow vessel or organ, etc.) and to the obstruction area (clot, plaque, or other obstruction). Once it is in the vicinity of the obstruction/constriction/narrowing, the user (physician/technician) can easily actuate the dilation mechanism(s) so that it is enlarged beyond its original size/diameter and dilate the narrowed passageway. Further, a similar mechanism can be deployed distal to the obstruction so that when the dilatation is occurring and fragments are dislodged during the therapy, the distal mechanism can trap them from moving downstream. These emboli can be trapped and then obliterated or removed at some later time.
A second embodiment of the instant invention, concerned with delivery or a drug/agent/solvent to the vessel wall, is directed to a tubular device, which has proximal and distal ends, constructed of monofilament or multifilament braids for use in the vascular system of the body. The braid, in a collapsed configuration, is elongated and would fit over the deflated balloon of an angioplasty catheter in a relaxed manner. Although it may be essentially the same length as the angioplasty balloon (or other dilatation device), it would likely extend proximal to and distal to the balloon on the shaft of the catheter, being of greater length than the balloon. It may extend to the distal tip of the catheter and may be affixed to the catheter shaft at or near the tip, either permanently or releasably. It may also be affixed to the catheter shaft proximally. It may have an attachment for engagement by a guide wire at its distal end or may be affixed to a wire or thread proximally. As will become apparent subsequently, a means for deploying the braid device and un-deploying, or contracting, the device other than the balloon may be necessary.
In a preferred version of this embodiment, the braids are made of a material, which has physical properties, which allow absorption of fluids or drugs into the braid material in the relaxed or non-expanded configuration. This would be performed outside the body before insertion of the device. After insertion and when the dilatation device is distended/expanded, the braid would expand with the device or as part of the device, be placed into a stretching tension and be compressed against the vessel wall. These two forces, stretching and compression, will cause the fluid, drug, solvent or other therapy residing within the absorbent material of the braid to be displaced from the braid. This agent would then diffuse into the wall, in the case of the passive diffusion configuration. In the case of the active transport system, electrical charges would be utilized to either draw the agent into the wall or to pump the agent into the wall. Similarly, the agent could be located between the dilatation mechanism and the outer braid or other material coating the dilatation mechanism.
Alternatively, the braid may be constructed of tiny tubular filaments, which may not have absorbent properties. However, because these filaments are tubular in nature, fluids containing drugs or other materials may be injected into them and delivered through them to the vessel wall. It is obvious that a means of injecting fluid into the filaments, such as another lumen in the catheter carrying the device, may be necessary. In addition, the exit site of the tubular filaments could take the form of small holes, porous material, slits, or just weakened areas of the filaments, just to name a few configurations. The tubular design of the filaments of the braid would also add strength to the device so that the outward radial forces needed for scaffolding purposes, described below, would be enhanced.
The braid may have other physical properties other than absorbency. The braid may possess enough rigidity to remain expanded after the initial balloon distention, providing scaffolding to prevent, or significantly lessen, elastic recoil of the dilated vessel. The braid is multi-stranded and may be either mono or multifilament braid.
Additionally, the aforementioned tubular braided mechanism is easily adapted for use at the exit site for a long term or indwelling catheter or other tube. This exit site is problematic for a variety of reasons; the most important of which is that it is a site when infection can occur. By using the tubular braid with the aforementioned disease inhibiting characteristics, the problems of this xe2x80x98exit sitexe2x80x99 are greatly reduced. It is a simple matter to manufacture the yarns/strands of the tubular braid using bio-resorbable materials well known to the medical device industry such as, but not limited to de- hydrated collagen strands. These strands readily absorb solvents/solutions and concurrently could be designed to be reabsorbed by the body in a pre-determined period of time.
While the device is augmented with several novel features to reduce disease and facilitate the angioplasty procedure, i.e., local drug delivery, scaffolding, ridges causing micro-fractures, flow through the porous braid, and single catheter insertion, any one of these features may be used alone or in combination with any of the other features to inhibit disease and facilitate the angioplasty procedure.
As well, while the discussions have addressed the uses of the device within the vascular system, the device may be utilized in the form described, or in a modified form, within other passageways in the body for local delivery of drugs, radiation, and other materials, scaffolding, hemostasis, disease treatment or prevention as well as other uses.